Low flows on the Rangitaiki River

Even before the summer’s drought began in earnest, the Rangitaiki River in the Eastern Bay of Plenty, has been victim to low flows, thanks to the TrustPower operated Matahina Dam upstream of Te Teko. On my February trip on the river our safety boat had only been in the water five minutes when it grounded on a rock below the towering 80 metre high concrete face of the dam.

Trustpower’s Matahina Dam on the Rangitaiki River.

TrustPower has a resource consent to operate the dam to hold water in Lake Matahina when demand for power is low, and to let it through to generate power during peak demand. TrustPower is allowed to let the river levels below the dam drop to 40 cumecs which is already pretty low.

In 2009 TrustPower applied to renew its consent, and wanted to halve the minimum flow from 40 cumecs to 20. These lower flows would have drastic effects on the river’s health and mauri, its ecology and people’s enjoyment of the river for fishing, boating and whitebaiting. And there would be less water to dilute the discharges from Fonterra’s Eltham dairy factory. There has been strong and unified opposition to the company’s proposal from iwi, recreationalists and farmers. It seems nobody wants the river lowered except TrustPower.

The Bay of Plenty Regional Council listened to the community’s concerns. While it agreed to TrustPower’s application to operate the dam for a further 35 years, it ruled that the minimum flows should remain at 40 cumecs. Showing an astonishing disregard for public views and the health of the Rangitaiki TrustPower appealed the Council’s decision.

Locals say TrustPower’s rapid changes to the amount of water it releases through the Matahina Dam help cause serious riverbank erosion.

If Trustpower can be persuaded to see reason, rather than wanting more profit at the river’s expense, the health of the Rangitaiki could improve. The recently formed Rangitaiki River Forum is tasked with preparing a plan for the river and it wants to improve Murupara’s sewage treatment for example. Forum members represent Ngati Whare, Ngati Manawa, Ngati Awa and Tuwharetoa ki Kawerau and the regional and district councils.

A low flow trial in December 2009. Flows were reduced to 26 cumecs, not as low as Trustpower wants.

With a gentle gradient and few rapids the Rangitaiki is an easy river to paddle below the dam with river vistas of pine trees, farmland with some native forest and many sites important to iwi.

On my trip I met many great river users on my day on the Rangitaiki and the community came out to celebrate the river together in Te Teko for a shared lunch afterwards. This is clearly a community which feels very strongly about their precious awa and they are prepared to stand up and fight for it in the Environment Court. They deserve our support for a positive outcome, for the river and the people.